package cn.itcast.zt.example.lock;

import cn.itcast.zt.annotation.ThreadSafe;
import lombok.extern.slf4j.Slf4j;

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Semaphore;
import java.util.concurrent.locks.StampedLock;

/**
 * create by zhangtian on 2018/4/8
 */
@Slf4j
@ThreadSafe
public class LockExample5 {
    // 请求总数
    public static int clientTotal = 5000 ;

    // 同时并发执行的线程数
    public static int threadTotal = 200 ;

    public static int count = 0 ;

    private static final StampedLock lock = new StampedLock() ;

    public static void main(String[] args) throws Exception {
        ExecutorService executorService = Executors.newCachedThreadPool() ;
        final Semaphore semaphore = new Semaphore(threadTotal) ;
        final CountDownLatch countDownLatch = new CountDownLatch(clientTotal) ;

        for (int i = 0; i < clientTotal; i++) {
            executorService.execute(()->{
                try {
                    semaphore.acquire();
                    add() ;
                    semaphore.release();
                } catch (InterruptedException e) {
                    log.error("exception", e);
                }
                countDownLatch.countDown();
            });
        }

        countDownLatch.await();
        executorService.shutdown();
        log.info("count:{}", count);
    }

    private static void add() {
        long stamp = lock.writeLock() ;
        count++;
        lock.unlock(stamp);
    }
}
